If people (perhaps the victim and/or her loved ones) are pissed off at a rapist, they might kill that rapist. Or they might torture the rapist. Or they might forcibly castrate the rapist. Or, they might forgive the rapist and rehabilitate. Or they might do something I haven’t listed.

The point is that there are no laws that codify what is to be done with rapists. Neither is there any law that protects them from so-called “mob justice”. Laws don’t exist in Anarchy.